1. Field
The present disclosure relates to zoom lens systems, imaging devices, and cameras.
2. Description of the Related Art
Size reduction and performance improvement are strongly required of cameras having image sensors performing photoelectric conversion, such as digital still cameras and digital video cameras (simply referred to as digital cameras, hereinafter).
Japanese Laid-Open Patent Publications Nos. 2011-209347, 2011-123337, 2011-090190, and 2010-039271 each disclose a lens system of a six-unit configuration including a first lens unit having positive optical power, a second lens unit having negative optical power, and a third lens unit having positive optical power, in which the first to third lens units move in zooming.
Japanese Laid-Open Patent Publication No. 2006-251462 discloses a lens system of a six-unit configuration including a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit having negative optical power, a fifth lens unit having positive optical power, and a sixth lens unit having negative optical power, in which the intervals between these lens units are varied to perform magnification change, and the fourth lens unit is moved along an optical axis to perform focusing.